J Nat Cancer Institute 2014 doi: 10.1093/jnci/dju169
Breast cancer encompasses at least four main subtypes (Nature 2012 490:61-70). Around one in five breast cancers express a gene called HER2. HER2-positive cancers grow and spread especially aggressively.
Trastuzumab (Herceptin), the first line treatment for HER2-positive cancers, blocks signals promoting growth sent from protein encoded by HER2. However, up to 70% of patients do not respond to or develop resistance to trastuzumab. Researchers,, have shown that a protein called avß6 helps breast cancer cells grow and spread.